The present disclosure relates to a fixing device fixing a toner image on a sheet and an image forming apparatus including this fixing device.
As one manner heating a fixing belt of a fixing device, a manner using a flat heater is known. The flat heater has a heat generating part having a longitudinal direction orthogonal to a conveying direction of a sheet, and is arranged so that the heat generating part faces to an inner circumference face of the fixing belt. The fixing belt is sandwiched between the flat heater and a pressuring roller.
A length in the longitudinal direction of the heat generating part is a length corresponding to the sheet of a maximum size and, if the sheet of a size smaller than it is used, heat consumption of both ends in the longitudinal direction through which the sheet does not pass is decreased. Thereupon, as shown in FIG. 8, a configuration is proposed, in which a plurality of heat generating parts 41 to 43 are arranged in the longitudinal direction and the heat generating part according to the size of the sheet is heated.
Concretely, the heat generating parts 41 to 43 have a plurality of resistance heat generating elements 40 arranged along one line parallel to the longitudinal direction. The heat generating part 41 is located at a center portion in the longitudinal direction and the heat generating parts 42 and 43 are located at both adjacent sides to it. At a side of the heat generating part 42, electrode parts 51 to 54 are arranged along one line parallel to the longitudinal direction. Feeders 61, 62 and 63 are respectively connected to right ends of the heat generating parts 41, 42 and 43 on a paper sheet of the figure. A feeder 64 is connected to left ends of the heat generating parts 41 to 43 on a paper sheet of the figure. The feeders 61, 62, 63 and 64 are respectively connected to the electrode parts 51, 52, 53 and 54. Further, a connector is attached at a position shifted to a right side from a left side of the electrode parts 51 to 54.
By contrast, as shown in FIG. 9, another configuration is proposed, in which the feeders 62 and 63 are connected to the electrode part 52 and the electrode part 53 is omitted so that a length in the longitudinal direction of the flat heater is shortened. However, in such a case, because the feeder 63 is arranged at a near side from the electrode parts 52 and 54 in an attaching direction of the connector, it is feared that the feeder 63 is scraped off by friction with a contacting portion of the connector when the connector is attached and conduction failure occurs.
Thereupon, conventionally, a technique of restraining conduction failure due to contact of the contacting portion and the flat heater when the connector is attached is researched. For example, a conventional connector includes a housing having an opening, and a contact terminal having a supporting face portion, a contacting portion and an engaging face portion and being electrically connected to an electrode part inserted in the opening by protruding operation to the opening. A restricting member pushes the contact terminal to retract the contacting portion from the opening, and thereby, restrict the contacting portion from coming into contact with a member inserted inside the opening, and separates the contact terminal to protrude the contacting portion to the opening.
However, the above-mentioned conventional configuration, a shape of the connector is complicated. Moreover, a size of the connector is enlarged.